THE EXTRACTION OF PLASMA 3-HYDROXY-17-OXO STEROID SULPHATES AND THE MEASUREMENT OF THE CONSTITUENT DEHYDROEPIANDROSTERONE SULPHATE AND ANDROSTERONE SULPHATE

1. A simple method for the extraction of 17-oxo steroid sulphates of plasma is described; glucosiduronates and orthophosphates are extracted, but to a smaller extent. 2. Four methods of analyses of the extracts are given and are relatively simple. Three of these are specific for steroid sulphates and two measure the sulphate conjugates directly. 3. Values for dehydroepiandrosterone sulphate and androsterone sulphate concentrations of normal and pathological plasmas are given.

OBSERVATIONS ON VITAMIN B12 IN SERUM AND CEREBROSPINAL FLUID IN MULTIPLE SCLEROSIS

There are several claims that B(12) concentrations in serum and cerebrospinal fluid are grossly abnormal in multiple sclerosis, but results are conflicting. This paper reports measurements of these concentrations in 40 serum samples and 23 samples of lumbar cerebrospinal fluid from cases of multiple sclerosis, and in appropriate controls, using Euglena gracilis, z strain. The serum concentrations were found to be normal; the mean concentration in cerebrospinal fluid was slightly reduced, but all values were within the control range. In both control samples and samples from cases of multiple sclerosis, the B(12) concentration in lumbar cerebrospinal fluid was correlated with the concentration in serum. There was no correlation between B(12) concentration and total protein in cerebrospinal fluid.A number of estimations of serum B(12) were also made with Lactobacillus leichmannii, after extraction in the presence and absence of cyanide. These showed a difference between cases of multiple sclerosis and controls, one interpretation of which might be that the serum in multiple sclerosis contains an abnormally low concentration of hydroxocobalamin.

HEAT STABILITY OF HUMAN PLACENTAL ALKALINE PHOSPHATASE

Alkaline phosphatase prepared from human placentae shows greater resistance to heat inactivation than any other known alkaline phosphatase of human origin. In the presence of magnesium this enzyme may be heated at 70 degrees C. for 30 minutes without loss of activity whereas other human alkaline phosphatases lose most of their activity on being heated at 56 degrees C. for this period of time. This heat stability is seen in freshly prepared enzyme, in alcohol-fractionated and freeze-dried material, and in the sera of individuals into whom placental alkaline phosphatase has been infused. The clinical implications of our observations are briefly indicated.

BIOCHEMICAL INVESTIGATION OF HISTIDINAEMIA

A 6-month-old child with a history of recurrent infections, convulsions, and retarded development had biochemical findings which were typical of histidinaemia. The enzyme histidase has been shown to be absent from the skin of the patient. The results of histidine-loading experiments in the parents of the child suggest that they may both metabolise this amino-acid abnormally. A simple method of estimating histidine in plasma and urine is described.

AN IMPROVED METHOD FOR THE SIMPLE AND ACCURATE COLORIMETRIC DETERMINATION OF UREA WITH EHRLICH'S REAGENT

An improved method for the colorimetric determination of urea is described. The method is simple, requiring a deproteinized filtrate obtained after treatment of a small quantity of whole oxalated blood, serum, plasma or urine with 12.5% trichloracetic acid containing 50 g. activated carbon. The addition of Ehrlich's reagent to this filtrate results in the immediate production of a stable yellow colour. The determination is accurate, very sensitive and rapid, taking place in only 10 minutes.

HYPERTRIGLYCERIDEMIA IN GOUT

Serum triglyceride levels were significantly higher in 34 patients with gout (42 mg. per 100 ml.) in comparison to the levels in 28 healthy men over 35 years of age (100 mg. per 100 ml.). There was no significant predictive relation between levels of serum uric acid and triglycerides in either group. No significant difference in serum cholesterol levels nor lipoprotein profile was apparent between the two groups. The patients with gout had been selected to exclude any manifestations of atherosclerosis or other disease known to be associated with abnormalities in circulating lipids. The results provide support for possible linkage of genetic factors influencing uric acid and triglyceride metabolism. The presence of hypertriglyceridemia in gout may be correlated with the increased incidence of arteriosclerosis.

REGULATION OF GLUCOSE OXIDATION IN THE WHITE RAT

The rate of oxidation of glucose has been measured in 43 rats acclimated to 30 C, at rates of turnover of 8–105 mg glucose carbon/100 g body wt. per hour (mg C/100 g·hr) by the technique of priming and continuous infusion of trace amounts of C14-glucose. This range of glucose turnover values had been obtained by using rats in various nutritive states or by continuous infusion of nonlabeled glucose. Oxidation was directly proportional to turnover between rates of turnover of 8 and 40 mg C/100 g·hr with a slope of about 0.5. At higher rates of turnover the ratio of oxidation to turnover decreased to 0.35, thus indicating that oxidation was approaching a maximum. At the highest rates of glucose turnover, a maximum of 63% of the respiratory CO2 was derived from body glucose, although the amount of non-labeled glucose carbon injected per minute exceeded the respiratory CO2 carbon by a factor of 1.8. Therefore, oxidation of glucose in the intact rat is closely regulated by its availability, but body glucose does not appear to serve as sole substrate for respiration even when its rate of turnover exceeds the respiratory output of carbon.